Shadparvar Abdol Ahad, Ghanipoor Mani, Mirhosseini Seyed Ziaoddin, Etebari Kayvan
Department of Animal Sciences, Faculty of Agriculture, University of Guilan, Rasht, Iran.
J Econ Entomol. 2005 Oct;98(5):1717-22. doi: 10.1093/jee/98.5.1717.
Using a deterministic model of profit equation compatible to cocoon production system in Iran, equations for estimating economic values of cocoon weight, shell weight, shell percentage, fecundity, fertility, and hatchability of three commercial varieties of silkworm Bombyx mori (L.) were derived. Economic values of these traits as well as their relative economic importance (REI) compared with cocoon weight were estimated. Estimates of economic value of a given trait differed among the varieties. Cocoon weight, shell weight, and shell percentage had the highest economic value in variety 107. The highest economic value for fecundity, fertility, and hatchability was estimated in variety 110. Shell weight and shell percentage were the most important production traits, and fecundity was the most important reproduction trait. The REI values of shell weight and shell percentage were higher than that of cocoon weight. The sensitivity of estimated economic values to principal factors of production system was studied by altering cocoon weight, shell percentage, fecundity, variable costs, and cocoon price by +/- 10%. The traits varied in the rate of sensitivity of their economic values to changes in production factors. Economic values of cocoon weight, fecundity, fertility, and hatchability had the most sensitivity to the changes in shell percentage. The most important factor affecting economic values of shell weight and shell percentage was the grade 1 cocoon price. Economic value equations provided in this study can help silkworm breeders to concentrate on the most important factors in predicting the future. Furthermore, when these factors change, silkworm breeders will be able to determine to what extent breeding goals have to change.
利用与伊朗蚕茧生产系统相适配的利润方程确定性模型，推导了估算家蚕（Bombyx mori (L.)）三个商业品种的茧重、壳重、壳率、产卵数、受精率和孵化率经济价值的方程。估算了这些性状的经济价值及其与茧重相比的相对经济重要性（REI）。给定性状的经济价值估计在不同品种间存在差异。在品种107中，茧重、壳重和壳率具有最高的经济价值。在品种110中，产卵数、受精率和孵化率的经济价值估计最高。壳重和壳率是最重要的生产性状，产卵数是最重要的繁殖性状。壳重和壳率的REI值高于茧重。通过将茧重、壳率、产卵数、可变成本和茧价分别变动±10%，研究了估计经济价值对生产系统主要因素的敏感性。各性状经济价值对生产因素变化的敏感程度各不相同。茧重、产卵数、受精率和孵化率的经济价值对壳率变化最为敏感。影响壳重和壳率经济价值的最重要因素是一级茧价格。本研究提供的经济价值方程可帮助蚕农关注预测未来的最重要因素。此外，当这些因素发生变化时，蚕农将能够确定育种目标必须改变的程度。
